It can be dangerous for a driver to use a handset communication device while driving, since the attention of the driver can be significant impaired while communicating using a handset communication device. This may lead to a traffic accident, thus causing personal injury and property loss to the driver, passenger and other people. Therefore, many countries, including China, England, Canada, the United States, etc., have promulgated relevant regulations to inhibit or restrict a driver's use of a handset communication device. Many prior art techniques have been proposed to control a driver's use of a handset communication device.
U.S. Pat. No. 6,262,657 discloses a driver alert system for controlling a driver's handset usage while in a dangerous driving state. A face image of a driver is captured by a CCD camera. An image processing unit is used to judge whether the driver is using a handset while driving by comparing the face image of the driver with a face image of the driver when not using a handset. A call detecting unit is also used to determine whether the driver is using a handset while driving by detecting the strength of a wireless signal transmitted from the handset.
CN 1980565A discloses an in-vehicle radio wave shielding apparatus which comprises detecting means for detecting whether a vehicle is in moving state, controlling means for judging whether the vehicle is in moving state, and shielding wave transmitting means. An output of the detecting means is connected to an input of the controlling means, an output of the controlling means is connected to an input of the shielding wave transmitting means, and a jammer is installed above the driver. Depending on whether the vehicle is in a moving state, the jammer transmits a shielding wave to shield radio waves of a certain frequency around the driver.